Lunch or Happy Hour @Twitter Headquarters near Civic Center in San Francisco. Tweet from the @Twisitor cam, Tour of the @Twoffice, Try the game room, Lounge on the roof deck, and Try 4 different cafes with sushi, juices, tapas, and healthy gourmet faire (and all you can eat bacon/popcorn). Or come to a Friday happy hour where there are fun themes and fun people.